This paper presents a secure scheme to enhance the transmission security of content-based hidden biometric data over insecure network. Encryp-tion, coding, spread spectrum modulation, and data hiding techniques are used to improve the security and secrecy of the transmitted templates. Secret keys are generated by the biometric image and used as the parameter value and initial condition of the chaotic maps, and each transaction session has different secret keys to protect from the attacks. Templates are encrypted by chaotic encryption, encoded by BCH encoding method, modulated by chaotic neural network parameter modulation (CNNPM), and then hid into the cover image. Experi-mental results show that the security, performance, and accuracy of the presented scheme is encouraging comparable with other methods found in the current literature.